ShieldBars

ShieldBars is an addon that displays your currently active shields.
Most of the commonly used shields are supported. It will only display something while there's an active shield on the player.
Use the options menu to show an example shield to help with customisation.

so i did 2 tot lfr's last night and didnt notice any issues seemed to work ok with soul leech for as much attention as i pay to it. usually just a glance to see if i have enough absorb up from it fr big damage or if i need to sacrifical pact for buffer :P

Previously if the same shield was applied twice (priest healing shield) Sheild Bars would only show the bar for the first shield applied and would then show the 2nd shield once the first expired. Now both shields are shown.

Here's the other shield additions I've added. (This list will grow as I test them.) I've not set the bar colors so they'll need to be adjusted for your liking.

Quick tests so far shows it updates the timer and the damage absorbed. It might help some other shield buffs as well which update without triggering the combat event update but that'll have to be tested still.

I took a quick look at Shield Tracker and it looks as if it re-scans every time something changes. Shield Bars only modifies what actually changes so it looks to be more efficient. Now, don't take my word on how difficult it will be to update Shield Bars. I'm not the author and am still learning how it works. The author might know a quick fix for it.